U.S. patent application number 13/761599 was filed with the patent office on 2013-08-15 for control apparatus for unmanned autonomous operating vehicle.
This patent application is currently assigned to HONDA MOTOR CO., LTD.. The applicant listed for this patent is HONDA MOTOR CO., LTD.. Invention is credited to Toshiaki Kawakami, Ryuichi Kimata, Hiroshi Kobayashi, Makoto Yamamura.
Application Number | 20130211648 13/761599 |
Document ID | / |
Family ID | 47747402 |
Filed Date | 2013-08-15 |
United States Patent
Application |
20130211648 |
Kind Code |
A1 |
Yamamura; Makoto ; et
al. |
August 15, 2013 |
CONTROL APPARATUS FOR UNMANNED AUTONOMOUS OPERATING VEHICLE
Abstract
In an apparatus for controlling an unmanned autonomous operating
vehicle having an electric motor supplied with power from a battery
for operating an operating machine, and magnetic sensors for
detecting intensity of a magnetic field of an area wire and
controlled to run about in an operating area defined by the area
wire through wheels driven by the prime movers to perform an
operation using the operating machine and to return to a charging
device installed on the area wire so as to charge the battery,
there is provided with a turn-back portion formed by bending the
area wire at an appropriate position and again bending the area
wire to return in a same direction with a predetermined space so as
to divide the operating area into a plurality of parts and vehicle
running is controlled to be prohibited from going across the
turn-back portion.
Inventors: |
Yamamura; Makoto; (Wako-shi,
Saitama, JP) ; Kawakami; Toshiaki; (Wako-shi,
Saitama, JP) ; Kobayashi; Hiroshi; (Wako-shi,
Saitama, JP) ; Kimata; Ryuichi; (Wako-shi, Saitama,
JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
HONDA MOTOR CO., LTD.; |
|
|
US |
|
|
Assignee: |
HONDA MOTOR CO., LTD.
Tokyo
JP
|
Family ID: |
47747402 |
Appl. No.: |
13/761599 |
Filed: |
February 7, 2013 |
Current U.S.
Class: |
701/22 |
Current CPC
Class: |
G05D 1/021 20130101;
G05D 1/0265 20130101; G05D 1/0225 20130101; G05D 2201/0208
20130101 |
Class at
Publication: |
701/22 |
International
Class: |
G05D 1/02 20060101
G05D001/02 |
Foreign Application Data
Date |
Code |
Application Number |
Feb 10, 2012 |
JP |
2012-027636 |
Claims
1. An apparatus for controlling an unmanned autonomous operating
vehicle having an electric motor supplied with power from a battery
for operating an operating machine, prime movers for driving
wheels, and magnetic sensors for detecting intensity of a magnetic
field of an area wire, the vehicle being controlled to run about in
an operating area defined by the area wire through wheels driven by
the prime movers to perform an operation using the operating
machine and to return to a charging device installed on the area
wire so as to charge the battery, wherein the improvement
comprises: a turn-back portion formed by bending the area wire at
an appropriate position and again bending the area wire to return
in a same direction with a predetermined space so as to divide the
operating area into a plurality of zones; and a running controller
adapted to control the vehicle to be prohibited from going across
the turn-back portion.
2. The apparatus according to claim 1, wherein the improvement
further comprises: a charging device detecting area set to be used
for detecting a position of the charging device, and the running
controller controls the vehicle to turn about when the vehicle is
determined to have reached the charging device detecting area and
subsequently run toward the area wire to be guided to the charging
device when the vehicle detects the intensity of the magnetic field
of the area wire to return to the charging device.
3. The apparatus according to claim 1, wherein the running
controller changes an entering direction of the vehicle to the
charging device whenever the vehicle is returned to the charging
device.
4. The apparatus according to claim 1, wherein the predetermined
space is determined based on the intensity of the magnetic field of
the area wire.
5. The apparatus according to claim 1, wherein the prime movers
comprises electric motors to be supplied with power from the
battery.
6. The apparatus according to claim 1, wherein the operating
machine comprises a lawn mower.
7. The apparatus according to claim 1, wherein the vehicle has a
charging terminal at its front to be connectable with the charging
device installed on the area wire.
8. The apparatus according to claim 1, wherein the charging device
is disposed with a coil radiating a magnetic field that forms the
charging device detecting area around the charging device.
9. A method for controlling an unmanned autonomous operating
vehicle having an electric motor supplied with power from a battery
for operating an operating machine, prime movers for driving
wheels, and magnetic sensors for detecting intensity of a magnetic
field of an area wire, the vehicle being controlled to run about in
an operating area defined by the area wire through wheels driven by
the prime movers to perform an operation using the operating
machine and to return to a charging device installed on the area
wire so as to charge the battery, wherein the improvement comprises
the step of: controlling the vehicle to be prohibited from going
across a turn-back portion formed by bending the area wire at an
appropriate position and again bending the area wire to return in a
same direction with a predetermined space so as to divide the
operating area into a plurality of zones.
10. The method according to claim 9, wherein the step of running
controlling controls the vehicle to turn about when the vehicle is
determined to have reached the charging device detecting area a
charging device detecting area set to be used for detecting a
position of the charging device, and subsequently run toward the
area wire to be guided to the charging device when the vehicle
detects the intensity of the magnetic field of the area wire to
return to the charging device.
11. The method according to claim 9, wherein the step of running
controlling changes an entering direction of the vehicle to the
charging device whenever the vehicle is returned to the charging
device.
12. The method according to claim 9, wherein the predetermined
space is determined based on the intensity of the magnetic field of
the area wire.
13. The method according to claim 9, wherein the prime movers
comprise electric motors to be supplied with power from the
battery.
14. The method according to claim 9, wherein the operating machine
comprises a lawn mower.
15. The method according to claim 9, wherein the vehicle has a
charging terminal at its front to be connectable with the charging
device installed on the area wire.
16. The method according to claim 9, wherein the charging device is
disposed with a coil radiating a magnetic field that forms the
charging device detecting area around the charging device.
Description
BACKGROUND
[0001] 1. Technical Field
[0002] An embodiment of the invention relates to a control
apparatus of an unmanned autonomous operating vehicle, particularly
to an apparatus for controlling an operating vehicle to
autonomously run about in an operating area to perform an operation
using a mounted operating machine.
[0003] 2. Background Art
[0004] Conventionally, there are proposed a variety of unmanned
autonomous operating vehicles that autonomously runs in operating
areas to perform operations using mounted operating machines such
as lawn-mowing blades, as taught, for example, by International
Publication No. WO 2005/074362.
[0005] In the reference, a magnetic sensor attached to a front end
of an operating vehicle detects the intensity of a magnetic field
of an area wire laid along a border of an operating area to
recognize the operating area, and a mounted operating machine
including lawn-mowing blades and installed with an electric motor
is driven to perform the operation in the recognized operating
area.
[0006] The motor of the vehicle in the technique stated in the
reference is supplied with power from a mounted battery. In order
to charge the battery, a charging device is disposed on the area
wire and when the remaining battery level is decreased, the vehicle
is controlled to follow the area wire by the aid of the magnetic
sensor to return to the charging device along the area wire.
SUMMARY
[0007] There are varous types of operating areas. In one case, an
operating area is divided into main areas and sub areas and those
areas are connected through narrow passages. The operation is
regularly performed in the main areas and it may suffice if the
operation is performed once in a while in the sub areas. The same
can be said when the operation is intended to be performed in a
certain part of one operating area.
[0008] Meanwhile, the vehicle disclosed in the reference is
configured to detect the area wire and follow the area wire to
return to the charging device when the remaining battery level is
decreased as mentioned above. In this case, if the operating area
is divided by different area wires, it is necessary to install the
charging devices for the respective divided areas,
disadvantageously.
[0009] An object of an embodiment of the invention is therefore to
overcome the foregoing drawback by providing a control apparatus
for an unmanned autonomous operating vehicle having an electric
motor that is mounted on a vehicle body and supplied with power
from a battery to drive an operating machine to perform an
operation, which apparatus can control the vehicle so as not to
perform the operation in a certain part, with the simple
structure.
[0010] In order to achieve the object, the embodiment of the
invention provides in the first aspect an apparatus for controlling
an unmanned autonomous operating vehicle having an electric motor
supplied with power from a battery for operating an operating
machine, prime movers for driving wheels, and magnetic sensors for
detecting intensity of a magnetic field of an area wire, the
vehicle being controlled to run about in an operating area defined
by the area wire through wheels driven by the prime movers to
perform an operation using the operating machine and to return to a
charging device installed on the area wire so as to charge the
battery, wherein the improvement comprises: a turn-back portion
formed by bending the area wire at an appropriate position and
again bending the area wire to return in a same direction with a
predetermined space so as to divide the operating area into a
plurality of parts; and a running controller adapted to control the
vehicle to be prohibited from going across the turn-back
portion.
[0011] In order to achieve the object, the embodiment of the
invention provides in the second aspect a method for controlling an
unmanned autonomous operating vehicle having an electric motor
supplied with power from a battery for operating an operating
machine, prime movers for driving wheels, and magnetic sensors for
detecting intensity of a magnetic field of an area wire, the
vehicle being controlled to run about in an operating area defined
by the area wire through wheels driven by the prime movers to
perform an operation using the operating machine and to return to a
charging device installed on the area wire so as to charge the
battery, wherein the improvement comprises the step of: controlling
the vehicle to be prohibited from going across a turn-back portion
formed by bending the area wire at an appropriate position and
again bending the area wire to return in a same direction with a
predetermined space so as to divide the operating area into a
plurality of parts.
BRIEF DESCRIPTION OF DRAWINGS
[0012] The above and other objects and advantages will be more
apparent from the following description and drawings in which:
[0013] FIG. 1 is a side view of a control apparatus for an unmanned
autonomous operating vehicle according to an embodiment of the
invention;
[0014] FIG. 2 is a plan view of the vehicle shown in FIG. 1;
[0015] FIG. 3 is a block diagram showing input and output of
devices mounted on the vehicle shown in FIG. 1;
[0016] FIG. 4 is a plan view showing an operating area where the
vehicle shown in FIG. 1 is to be run;
[0017] FIG. 5 is a block diagram showing the configuration of the
charge ST (station) shown in FIG. 4;
[0018] FIG. 6 is an explanatory view showing a charging process at
the charge ST shown in FIG. 5;
[0019] FIG. 7 is an explanatory view showing a magnetic field of an
area wire embedded in the operating area shown in FIG. 4;
[0020] FIG. 8 is a flowchart showing the operation of the apparatus
shown in FIG. 1, i.e., the operation in the case of applying a
running trajectory (1) shown in FIG. 4;
[0021] FIG. 9 is a flowchart showing the operation of the apparatus
shown in FIG. 1, i.e., the operation in the case of applying a
running trajectory (2) shown in FIG. 4; and
[0022] FIG. 10 is a flowchart showing the operation of the
apparatus shown in FIG. 1, i.e., the operation in the case of
applying a running trajectory (3) shown in FIG. 4.
DESCRIPTION OF EMBODIMENT
[0023] A control apparatus of an unmanned autonomous operating
vehicle according to an embodiment of the present invention will
now be explained with reference to the attached drawings.
[0024] FIG. 1 is a side view of a control apparatus for an unmaned
autonomous operating vehicle according to an embodiment of the
invention, FIG. 2 is a plan view of the vehicle shown in FIG. 1,
FIG. 3 is a block diagram showing input and output of devices
mounted on the vehicle shown in FIG. 1 and FIG. 4 is a plan view
showing an operating area where the vehicle shown in FIG. 1 is to
be run.
[0025] As shown in FIGS. 1 and 2, symbol 10 indicates an unmanned
autonomous operating vehicle. The vehicle 10 has a vehicle body 12
and wheels 14. The body 12 includes a chassis 12a and a frame 12b
attached to the chassis 12a, while the wheels 14 include right and
left front wheels 14a of a relatively small diameter that are fixed
on the forepart of the chassis 12a through a stay 12a1, and right
and left rear wheels 14b of a relatively large diameter that are
directly attached to the chassis 12a.
[0026] Blades (rotary blades; operating machine) 16 for mowing lawn
are attached in the center or thereabout of the chassis 12a, and an
electric motor (hereinafter called the "operating motor") 20 is
installed above the blades 16. The blades 16 are connected to the
operating motor 20 to be driven and rotated thereby.
[0027] The blades 16 are also connected to a blade height
adjustment mechanism 22 to be manually manipulated by an operator
(user). The blade height adjustment mechanism 22 is equipped with a
screw (not shown) to be manually turned by the operator for
adjusting the height of the blades 16 from a contacting ground
GR.
[0028] Two electric motors (prime movers; hereinafter called the
"running motors") 24 are attached to the chassis 12a of the vehicle
10 to the rear of the blades 16. The running motors 24 are
connected to the right and left rear wheels 14b to operate them so
that the rear wheels 14b are rotated in the normal (forward
running) direction or reverse (backward running) direction
independently of each other to make the vehicle 10 run on the
ground GR. In other words, the front wheels 14a serve as the free
wheels while the rear wheels 14b serve as the driven wheels. The
blades 16, operating motor 20, running motors 24, etc., are covered
by the frame 12b.
[0029] A charging unit (including an AC/DC converter) 26 and
battery 30 are accommodated at the rear of the vehicle 10 and two
charging terminals 32 are attached to the frame 12b at the front of
the vehicle 10 to protrude forward to be connectable with the
charging device. Each of the terminals 32 has a contact point 32a
on a side facing the other contact point 32a.
[0030] The terminals 32 are connected to the charging unit 26
through wiring and the charging unit 26 is connected to the battery
30 through wiring. The operating and running motors 20, 24 are
connected to the battery 30 through wiring to be supplied with
power therefrom. The wiring is not illustrated in FIGS. 1 and
2.
[0031] Thus, the vehicle 10 is constituted as a four-wheel,
unmanned, electric autonomous operating vehicle (lawn-mowing
vehicle) that is, for instance, about 600 millimeters long, 300
millimeters wide and 300 millimeters high.
[0032] A front end of the vehicle 10 is installed with two, i.e.,
right and left magnetic sensors (magnetism detector) 34. The frame
12b is attached with a contact sensor 36. When the frame 12b comes
off from the chassis 12a upon having contact with an obstacle and
such, the contact sensor 36 outputs an ON signal.
[0033] A housing box is provided in the center or thereabout of the
vehicle 10 to house a board 40 on which an Electronic Control Unit
(ECU; Controller) 42 including a microcomputer having a CPU, ROM,
RAM, etc., is installed. The board 40 is also installed in the
vicinity of the ECU 42 with a Yaw sensor (angular velocity sensor)
44 that produces an output or signal indicative of angular velocity
(yaw rate) generated about a z-axis in the center of gravity of the
vehicle 10 and with a G sensor (acceleration sensor) 46 that
produces an output or signal indicative of an acceleration G acting
on the vehicle 10 in the X, Y and Z (three-axis) directions.
[0034] A wheel speed sensor 50 is installed near the rear (driven)
wheel 14b to produce an output or signal representing a wheel speed
thereof A lift sensor 52 is installed between the chassis 12a and
frame 12b to output an ON signal when the frame 12b is lifted from
the chassis 12a by the operator or the like.
[0035] A current/voltage sensor 54 is installed at the battery 30
to produce an output or signal indicative of SOC (State Of Charge)
of the battery 30. The vehicle 10 is installed with a main switch
56 and emergency stop switch 60 to be manipulated by the
operator.
[0036] The outputs of the foregoing magnetic sensors 34, contact
sensor 36, Yaw sensor 44, G sensor 46, wheel speed sensor 50, lift
sensor 52, current/voltage sensor 54, main switch 56 and emergency
stop switch 60 are sent to the ECU 42.
[0037] The upper surface of the frame 12b of the vehicle 10 is
widely cut away and a display 62 is installed therein. The display
62 is connected to the ECU 42 to show a mode of the vehicle's
status such as an operating mode in response to a command sent from
the ECU 42.
[0038] Next, the explanation will be made on the operating area 70
where the vehicle 10 is to be run. As shown in FIG. 4, the
operating area 70 has a substantially-rectangular shape and a lower
portion (in the drawing) is greatly concaved inwardly so that a
zone 1 (main area) on the left side and a zone 2 (sub area) on the
right side are formed. The zones 1, 2 are interconnected by a
narrow passage.
[0039] The operating area 70 is defined by an area wire (electric
wire) 72 that is embedded (laid) along a border of land L and a
charge ST (station) 74 is provided on the area wire 72. The charge
ST 74 is disposed with an ST coil 76. A magnetic field radiated
from the ST coil 76 forms a charging device detecting area 76a of a
circle with center at the charge ST 74 with a radius of about one
meter. Thus, the charge ST (charging device) 74 is disposed with
the coil 76 radiating a magnetic field that forms the charging
device detecting area 76a around the charge ST 74.
[0040] As shown in FIG. 5, the charge ST 74 has a charging device
84 connected to a commercial power source 80 through a socket 82,
and a charging terminal 86 that is connected to the charging device
84 and connectable to the contact points 32a of the charging
terminals 32 of the vehicle 10 through its contact points. The
charging terminal 86 is shown in FIG. 6 (the contact points thereof
are not illustrated).
[0041] The charging device 84 has an AC/AC converter 84a, an
Electronic Control Unit (ECU) 84b that includes a microcomputer
similarly to the ECU 42 and controls the operation of the AC/AC
converter 84a, and a signal generator 84c that supplies alternating
current to the area wire 72 and ST coil 76 to generate signals.
[0042] Alternating current coming from the commercial power source
80 through the socket 82 is appropriately stepped down by the AC/AC
converter 84a of the charging device 84 and, when the vehicle 10 is
returned and connected to the charge ST 74 through the charging
terminals 32 and 86, the current is sent to the vehicle 10 to
charge the battery 30 through the charging unit 26.
[0043] As shown in FIG. 4, the area wire 70 is bent at an
appropriate position, i.e., a position near the narrow passage
connecting the zone 1 to the zone 2, and again bent to return in
the same direction with a predetermined space (direction) w. In
other words, a turn-back portion 72a is formed at the area wire 70,
whereby the operating area 70 is divided into a plurality of zones,
i.e., two (right and left) zones in the illustrated example. As
described later, in this embodiment, when the vehicle 10 is run
about to perform the operation, the vehicle 10 is prohibited from
going across the turn-back portion 72a so as not to perform the
operation in a certain part (zone 2) of the operating area 70.
[0044] The operation of detecting the operating area 70 will be
explained. Upon power supply from the signal generator 84c, a
magnetic field is generated around the area wire 72. The intensity
of the magnetic field varies depending on the entire length of the
area wire 72 and also varies depending on a distance d from the
area wire 72 as shown in FIG. 7.
[0045] The intensity of the magnetic field of the area wire 72 is
detected by the magnetic sensors 34 attached to the vehicle 10 and
sent to the ECU 42. Based on the detected values, the ECU 42
detects a position of the subject vehicle (autonomous operating
vehicle 10) with respect to the area wire 72 (i.e., whether the
subject vehicle is positioned inside or outside the operating area
70) and the distance of the subject vehicle from the area wire 72
(i.e., from the border of the operating area 70).
[0046] More specifically, as shown in FIG. 7, when the subject
vehicle is moved from the inside of the operating area 70 to the
outside thereof in a direction indicated by an arrow a, as the
distance from the area wire 72 is reduced (as the subject vehicle
is moved closer to the area wire 72), the intensity of the magnetic
field is gradually increased on a positive side and afterward,
decreased. When the subject vehicle is positioned on the area wire
72, the intensity becomes zero. Subsequently, when the distance
from the area wire 72 is again increased, the intensity exhibits
the similar characteristics on a negative side. Also when the
subject vehicle is moved from the inside of the operating area 70
to the outside thereof in a direction indicated by an arrow b, the
characteristics similar to the above pattern are exhibited.
[0047] In FIG. 4, the predetermined space w at the turn-back
portion 72a of the area wire 72 is determined based on the
intensity of the magnetic field of the area wire 72. Specifically,
in order to avoid a situation where the magnetic fields at two
close points of the area wire 72 are canceled out and become
undetectable, the predetermined space w is appropriately set, e.g.,
set to 200 millimeters.
[0048] The operation of the vehicle 10 will be explained. The
height of the blades 16 is manually adjusted by the operator
through the blade height adjustment mechanism 22 in accordance with
a growing condition of the lawn in the operating area 70. When the
main switch 56 is switched on so that the ON signal is outputted,
the ECU 42 starts to be operated and enters the operating mode to
mow the lawn.
[0049] In the operating mode, the ECU 42 calculates a power supply
control value with which a vehicle speed detected from the output
of the wheel speed sensor 50 becomes a predetermined value and
supplies the calculated value to the running motors 24 through a
driver 24a to make the vehicle 10 run about. Further, the ECU 42
calculates a power supply control value with which rotational
speeds of the blades 16 become a predetermined value and supplies
the calculated value to the operating motor 20 through a driver 20a
to operate the blades 16 to perform the operation.
[0050] To be more specific, in the operating mode, the ECU 42 makes
the vehicle 10 run about randomly (or in accordance with an
operation pattern) to perform the operation within the operating
area 70. When determining that the vehicle 10 has moved out of the
operating area 70 based on the outputs of the magnetic sensors 34,
the ECU 42 changes a running direction detected based on the output
of the Yaw sensor 44 by a predetermined angle so that the vehicle
10 comes back to the inside of the operating area 70.
[0051] Since the right and left rear (driven) wheels 14b are
configured so that they are driven by the running motors 24 to
rotate in the normal and reverse directions independently or
separately from each other, when the motors 24 are rotated in the
normal direction at the same speed, the vehicle 10 is run straight,
whilst when they are rotated in the normal direction at different
speeds, the vehicle 10 is turned toward a side of lower rotational
speed. When one of the motors 24 is rotated in the normal direction
and the other is rotated in the reverse direction, since the rear
wheels 14b are rotated in the same direction as the associated
motor's rotation, the vehicle 10 is turned at the same position
(which is so-called pivot turn).
[0052] Thus, in the operating mode, the ECU 42 makes the vehicle 10
run about within the operating area 70 while changing the running
direction thereof randomly whenever the vehicle 10 reaches the area
wire 72, and drives the blades 16 to perform the operation.
[0053] Further, in the operating mode, the ECU 42 monitors the SOC
of the battery 30 based on the output of the current/voltage sensor
54 and when the remaining battery level is decreased to a
predetermined level, transitions to a return mode in which the
vehicle 10 is returned to the charge ST 74 to charge the battery 30
by the charging device 84. Running trajectories (or routes) (1) to
(3) to follow in the operating mode and return mode are shown in
FIG. 4. Note that those trajectories (1) to (3) are only examples
and a variety of trajectories other than those can be applied in
accordance with the situation.
[0054] Further, an entering direction of the vehicle 10 to the
charge ST 74 is alternately changed between a CW (Clockwise) and
CCW (Counterclockwise), as viewed from above of the operating area
70 (shown in FIG. 4), whenever the vehicle 10 is returned. It is
carried out by setting an appropriate flag in the RAM of the ECU
42.
[0055] In the operating mode and return mode, when any of the
contact sensor 36, lift sensor 52 and emergency stop switch 60
produces the ON signal, the ECU 42 stops the operating and running
motors 20, 24 to stop the operation and running of the vehicle
10.
[0056] FIGS. 8 to 10 are flowcharts showing operations of the ECU
42, i.e., operations (controls) corresponding to the running
trajectories (1) to (3) shown in FIG. 4.
[0057] FIG. 8 is a flowchart corresponding to the running
trajectory (1). The illustrated program applies the case where the
operation is performed only in the zone 1.
[0058] This program begins under a condition where the vehicle 10
has a connection with the charging device 84 at the charge ST 74 to
charge the battery 30 (S10). When the battery 30 has been fully
charged, the vehicle 10 is run backward and turned about (S12,
S14), and the status is changed to the operating mode in which the
vehicle 10 is run about within the operating area 70 randomly to
mow the lawn (S16). It is determined whether the remaining battery
level of the battery 30 is decreased (i.e., becomes equal to or
less than the predetermined level) (S18) and until the remaining
battery level is determined to have been decreased, the mowing
operation is continued (S16, S18).
[0059] In the operating mode, the ECU 42 operates the motors 24 to
drive the wheels 14 to run about the vehicle 10 in the operating
area 70, while operating the motor 20 to drive the blades 16 to
perform the operation. The ECU 42 determines the turn-back portion
72a of the area wire 72 as the inside, outside and inside of the
operating area 70, based on the outputs of the magnetic sensors
34.
[0060] At that time, in the operating mode, the ECU 42 compares a
time period that the vehicle 10 is determined to be in the outside
of the operating area 70 with an appropriate threshold value. The
comparison result is used to control the vehicle 10, i.e., prohibit
the vehicle 10 from going across the turn-back portion 72a so as
not to perform the operation in the zone 2.
[0061] When the remaining battery level is determined to be
decreased to the predetermined level, the mowing operation is
stopped, the running motors 24 are controlled to run the vehicle 10
straight (S20), the area wire 72 is detected based on the outputs
of the magnetic sensors 34, and the vehicle 10 is moved out of the
operating area 70 and stopped (S22).
[0062] In the case of applying the trajectory (1), since the
entering direction of the vehicle 10 when it is returned to the
charge ST 74 is set as the CCW, the vehicle 10 is restarted to turn
in counterclockwise (CCW) direction (S24), and the above process is
repeated until the area wire 72 is detected based on the outputs of
the magnetic sensors 34 and it is confirmed that the vehicle 10 has
come inside the operating area 70 (S26).
[0063] Next, based on the detected magnetic field intensity of the
area wire 72, the operations of the running motors 24 are
controlled to run the vehicle 10 on the area wire 72 (S28).
Specifically, based on the outputs of the magnetic sensors 34, the
ECU 42 controls amounts of power to be supplied to the running
motors 24 using a feedback control law such as a proportional term
so that a front portion of the vehicle 10 is slightly swung the
right and left so that the front portion is positioned inside and
outside the operating area 70 alternately, thereby controlling the
vehicle 10 to run on or along the area wire 72.
[0064] Next, it is determined whether the charge ST 74, i.e., the
charging device detecting area 76a is detected by detecting the
magnetic field of low intensity generated from the ST coil 76 using
the magnetic sensors 34 and comparing it with an appropriate
threshold value (S30). Whenever the result in S30 is negative, the
program returns to S28 to repeat the foregoing process.
[0065] When the result in S30 is affirmative, the running speed is
decreased and the vehicle 10 is controlled to enter the charge ST
74 in the CCW direction, whereby the charging terminals 32 of the
vehicle 10 are connected to the charging terminal 86 to charge the
battery 30 (S32).
[0066] FIG. 9 is a flowchart corresponding to the running
trajectory (2) shown in FIG. 4.
[0067] This program also begins under a condition where the vehicle
10 has a connection with the charging device 84 at the charge ST 74
to charge the battery 30 (S100). The vehicle 10 is run backward,
and turn about (S102, S104), and then run on the area wire 72 to
follow a trajectory a to move to the zone 2 (S106).
[0068] Next, it is determined whether the vehicle 10 has reached a
desired point in the zone 2 (S108). The desired point is set to a
position that can be recognized based on the output of the wheel
speed sensor 50 as where the vehicle 10 should reach after starting
to run backward in S102 and running a predetermined distance, for
example.
[0069] Next, the vehicle 10 is controlled to turn about, enter the
operating mode to run about within the operating area 70 randomly
to mow the lawn, and continue the mowing operation until the
remaining battery level is determined to have been decreased (S110
to S114). In the operating mode in S112, the ECU 42 prohibits the
vehicle 10 from going across the turn-back portion 72a so as not to
perform the operation in the zone 1.
[0070] When the remaining battery level is determined to be
decreased to the predetermined level in S114, the mowing operation
is stopped, the running motors 24 are controlled to run the vehicle
10 straight (S116), the area wire 72 is detected based on the
outputs of the magnetic sensors 34, and the vehicle 10 is moved out
of the operating area 70 and stopped (S118).
[0071] In the case of applying the trajectory (2), since the
entering direction of the vehicle 10 when it is returned to the
charge ST 74 is set as the CW, the vehicle 10 is restarted to turn
in clockwise (CW) direction (S120), and the above process is
repeated until the area wire 72 is detected based on the outputs of
the magnetic sensors 34 and it is confirmed that the vehicle 10 has
come inside the operating area 70 (S122).
[0072] Next, based on the detected magnetic field intensity of the
area wire 72, the operations of the running motors 24 are
controlled to run the vehicle 10 on the area wire 72 to follow a
trajectory b until the charge ST 74 is detected (S124). In this
embodiment, it is configured so that the return trajectory (route)
b is set similarly to the outward trajectory (route) a.
[0073] Although the vehicle 10 can take a route on an upper side of
the area wire 72 in FIG. 4 (where the turn-back portion 72a is
formed) to return to the charge ST 74, it results in a longer
running distance to the charging device 84. Therefore, it is
configured so that, when the vehicle 10 is moved to a distant zone
(zone 1), the vehicle 10 is controlled to follow the same
trajectory as that it took when it came.
[0074] When the charge ST 74 is detected, as shown in the drawing,
the vehicle 10 is turned about (S128). Then, the area wire 72 is
detected and the vehicle 10 is moved out of the operating area 70
and stopped (S130). The vehicle 10 is turned in the CCW direction
until the area wire 72 is detected (S132, S134). Subsequently, the
vehicle 10 is controlled to enter the charge ST 74 in the CCW
direction, whereby the charging terminals 32 of the vehicle 10 are
connected to the charging terminal 86 to charge the battery 30
(S136). Specifically, upon reaching the charging device detecting
area 76a, the vehicle 10 is turn about and run toward the area wire
72 to be guided to the charging device 84.
[0075] FIG. 10 is a flowchart corresponding to the running
trajectory (3) shown in FIG. 4.
[0076] The processes of S200 to S220 are conducted similarly to
those of S10 to S30 in the FIG. 8 flowchart (except for the turning
direction). When the charge ST 74 is detected, similarly to S128 to
S136 in the FIG. 9 flowchart, the vehicle 10 is controlled to turn
about (S222), move out of the operating area 70 and stop (S224),
turn in the CCW direction until the area wire 72 is detected (S226,
S228), and enter the charge ST 74 in the CCW direction, whereby the
charging terminals 32 of the vehicle 10 are connected to the
charging terminal 86 to charge the battery 30 (S230).
[0077] Note that the programs of the FIGS. 8 to 10 are repeated in
the numerical order. As a result, the number of operations to be
performed in the zone 2 can be reduced to a half of that in the
zone 1.
[0078] As stated above, the embodiment is configured to have an
apparatus and method for controlling an unmanned autonomous
operating vehicle (10) having an electric motor (20) supplied with
power from a battery (30) for operating an operating machine (16),
prime movers (24) for driving wheels (14), and magnetic sensors
(34) for detecting intensity of a magnetic field of an area wire
(72), the vehicle being controlled to run about in an operating
area (70) defined by the area wire through wheels driven by the
prime movers to perform an operation using the operating machine
and to return to a charging device (74) installed on the area wire
so as to charge the battery, characterized in that: a turn-back
portion (72a) formed by bending the area wire at an appropriate
position and again bending the area wire to return in a same
direction with a predetermined space so as to divide the operating
area into a plurality of parts; and a running controller (42, S16,
S112, S206) adapted to control the vehicle to be prohibited from
going across the turn-back portion.
[0079] With this, since the turn-back portion 72a is provided, it
becomes possible to control the vehicle 10 so as not to perform the
operation in a certain part of the operating area 70. Further,
since it is configured to only bend the area wire 72 locally and
another device such as an additional charging device is not needed,
the structure can be simple.
[0080] In the apparatus and method, the improvement further
comprises: a charging device detecting area (76a) set to be used
for detecting a position of the charging device, and the running
controller controls the vehicle to turn about when the vehicle is
determined to have reached the charging device detecting area and
subsequently run toward the area wire to be guided to the charging
device when the vehicle detects the intensity of the magnetic field
of the area wire to return to the charging device (42, S124-S136,
S218-S230). With this, in addition to the above effects, it becomes
possible to shorten the running distance of the vehicle 10 when it
is returned to the charging device 84 to charge the battery 30.
[0081] In the apparatus and method, the running controller changes
an entering direction of the vehicle to the charging device
whenever the vehicle is returned to the charging device. With this,
in addition to the above effects, it becomes possible to prevent
many tracks or grooves from being formed on the area wire 72 by
wheels 14 of the vehicle 10.
[0082] In the apparatus and method, the predetermined space is
determined based on the intensity of the magnetic field of the area
wire. With this, in addition to the above effects, when the
intensity of the magnetic field of the area wire 72 is detected to
run on the area wire 72, it becomes possible to avoid a situation
where the magnetic fields at two close points of the area wire 72
are canceled out and become undetectable, so that the vehicle's
running is not adversely affected.
[0083] In the apparatus and method, the prime movers (24) comprise
electric motors to be supplied with power from the battery. With
this, in addition to the above effects, it becomes possible to
reduce the noise compared to a case that an engine is employed.
[0084] In the apparatus and method, the operating machine (16)
comprises a lawn mower. With this, in addition to the above
effects, in the mowing operation in which the operating area 70 is
required to have the good appearance after the operation, it
becomes possible to prevent many tracks or grooves from being
formed on the area wire 72 by wheels 14 of the vehicle 10 and also
avoid needlessly damaging the lawn.
[0085] In the apparatus and method, the vehicle has a charging
terminal (32) at its front to be connectable with the charging
device installed on the area wire. With this, it becomes possible
to charge the battery 30 more easily.
[0086] In the apparatus and method, the charging device is disposed
with a coil (76) radiating a magnetic field that forms the charging
device detecting area around the charging device. With this, it
becomes possible to detect the charging device (charge ST) 74.
[0087] It should be noted that, in the foregoing, although the
electric motor is applied as the prime mover, it may be an internal
combustion engine or a hybrid of an engine and electric motor.
[0088] It should also be noted that, although the lawn-mowing
blades are exemplified as the operating machine, but it should not
be limited thereto and any machine can be applied if it is used for
maintaining the appearance of the operating area.
[0089] Japanese Patent Application No. 2012-027636, filed on Feb.
10, 2012 is incorporated by reference herein in its entirety.
[0090] While the invention has thus been shown and described with
reference to specific embodiments, it should be noted that the
invention is in no way limited to the details of the described
arrangements; changes and modifications may be made without
departing from the scope of the appended claims.
* * * * *